code: def on_draw(self, event):
      gloo.set_clear_color((0, 1, 0))
      gloo.clear()
  
file_path: vispy/vispy/app/backends/tests/test_rfb.py
imports: import numpy
  from vispy import gloo
  from vispy.app import Application, Canvas
  from vispy.app.backends import _jupyter_rfb
  from vispy.testing import run_tests_if_main, requires_application
  import pytest
label_desc: Use image node_id 1 for calling the MyCanvas obj's underlying member method code with example usage: obj.on_draw(event) without return types